It would be impossible to list all the GDPR abuses Wikipedians have committed over the years. Most were in the USA or UK, so the EU law would not apply, but there are several outrageous violations involving EU member citizens. Anyone remember MoiraMoira? How about endless dirty tricks involving the "seeeekret" Wikipediametric mailing list?.......three months ago, the Italian data protection authority ruled that Wikipedia is not really exempt from GDPR. This brings out hopes that their notorious LTA doxspace will one day be shut down and Wikipedia gets a huge fine as a comeuppance.
https://www.rplt.it/en/wikipedia-gdpr-data-protection/
Like the contemplated removal of Section 230 protections in the US, this will cost the WMF a LOT of money and goodwill. And they won't be able to openly abuse people as they always have before. So they will fight it tooth and nail.